1. /******************************************************************************/
  3. #define F_CPU 16000000UL
  5. #include <avr/io.h>
  6. #include <util/delay.h>
  8. #include <avr/sleep.h>
  10. #include <avr/interrupt.h>
  12. /******************************************************************************/
  14. int main(void)
  15. {
  16. cli();
  18. DDRD &= ~_BV(DDRD0); // set as input
  19. PORTD |= _BV(PORTD0); // enable pull-up
  21. DDRB |= _BV(DDB5);
  22. PORTB |= _BV(PINB5); // initialize to high
  24. PCICR |= _BV(PCIE2); // set PCIE2 to enable PCMSK2 scan
  25. PCMSK2 |= _BV(PCINT16); // set PCINT16 to trigger an interrupt on state change
  28. sei(); // turn on interrupts
  30. while (1) asm volatile ("nop"::);
  31. }
  33. /******************************************************************************/
  35. ISR (PCINT2_vect) {}
  37. /******************************************************************************/